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Commit 8b1fded7 authored by David Herrmann's avatar David Herrmann Committed by Jiri Kosina
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HID: wiimote: add "bboard_calib" attribute 



Balance-Boards provide 3 16bit calibration values for each of the 4
sensors. We provide these now as 192bit value via a new "bboard_calib"
sysfs attribute.
We also re-read the calibration data from the device whenever user-space
attempts to read this file. On normal Nintendo boards, this always
produces the same results, however, on some 3rd party devices these values
change until the device is fully initialized. As I have currently no idea
how long to wait until it's ready (sometimes takes up to 10s?) we provide
a simple workaround for users by reading this file.

If we, at some point, figure out how it works, we can implement it in the
kernel and provide offline data via "bboard_calib". This won't break
user-space then.

Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent c7da0867

Documentation/ABI/testing/sysfs-driver-hid-wiimote

+15 −0
Original line number Diff line number Diff line
@@ -42,3 +42,18 @@ Description: While a device is initialized by the wiimote driver, we perform 
			gen10: First Wii Remote generation

			gen20: Second Wii Remote Plus generation (builtin MP)

			balanceboard: Wii Balance Board



What:		/sys/bus/hid/drivers/wiimote/<dev>/bboard_calib

Date:		May 2013

KernelVersion:	3.11

Contact:	David Herrmann <dh.herrmann@gmail.com>

Description:	This attribute is only provided if the device was detected as a

		balance board. It provides a single line with 3 calibration

		values for all 4 sensors. The values are separated by colons and

		are each 2 bytes long (encoded as 4 digit hexadecimal value).

		First, 0kg values for all 4 sensors are written, followed by the

		17kg values for all 4 sensors and last the 34kg values for all 4

		sensors.

		Calibration data is already applied by the kernel to all input

		values but may be used by user-space to perform other

		transformations.

drivers/hid/hid-wiimote-modules.c

+67 −1
Original line number Diff line number Diff line
@@ -1380,6 +1380,60 @@ static void wiimod_bboard_close(struct input_dev *dev) 
	spin_unlock_irqrestore(&wdata->state.lock, flags);

}



static ssize_t wiimod_bboard_calib_show(struct device *dev,

					struct device_attribute *attr,

					char *out)

{

	struct wiimote_data *wdata = dev_to_wii(dev);

	int i, j, ret;

	__u16 val;

	__u8 buf[24], offs;



	ret = wiimote_cmd_acquire(wdata);

	if (ret)

		return ret;



	ret = wiimote_cmd_read(wdata, 0xa40024, buf, 12);

	if (ret != 12) {

		wiimote_cmd_release(wdata);

		return ret < 0 ? ret : -EIO;

	}

	ret = wiimote_cmd_read(wdata, 0xa40024 + 12, buf + 12, 12);

	if (ret != 12) {

		wiimote_cmd_release(wdata);

		return ret < 0 ? ret : -EIO;

	}



	wiimote_cmd_release(wdata);



	spin_lock_irq(&wdata->state.lock);

	offs = 0;

	for (i = 0; i < 3; ++i) {

		for (j = 0; j < 4; ++j) {

			wdata->state.calib_bboard[j][i] = buf[offs];

			wdata->state.calib_bboard[j][i] <<= 8;

			wdata->state.calib_bboard[j][i] |= buf[offs + 1];

			offs += 2;

		}

	}

	spin_unlock_irq(&wdata->state.lock);



	ret = 0;

	for (i = 0; i < 3; ++i) {

		for (j = 0; j < 4; ++j) {

			val = wdata->state.calib_bboard[j][i];

			if (i == 2 && j == 3)

				ret += sprintf(&out[ret], "%04x\n", val);

			else

				ret += sprintf(&out[ret], "%04x:", val);

		}

	}



	return ret;

}



static DEVICE_ATTR(bboard_calib, S_IRUGO, wiimod_bboard_calib_show, NULL);



static int wiimod_bboard_probe(const struct wiimod_ops *ops,

			       struct wiimote_data *wdata)

{
@@ -1415,6 +1469,13 @@ static int wiimod_bboard_probe(const struct wiimod_ops *ops, 
	if (!wdata->extension.input)

		return -ENOMEM;



	ret = device_create_file(&wdata->hdev->dev,

				 &dev_attr_bboard_calib);

	if (ret) {

		hid_err(wdata->hdev, "cannot create sysfs attribute\n");

		goto err_free;

	}



	input_set_drvdata(wdata->extension.input, wdata);

	wdata->extension.input->open = wiimod_bboard_open;

	wdata->extension.input->close = wiimod_bboard_close;
@@ -1444,10 +1505,13 @@ static int wiimod_bboard_probe(const struct wiimod_ops *ops, 


	ret = input_register_device(wdata->extension.input);

	if (ret)

		goto err_free;

		goto err_file;



	return 0;



err_file:

	device_remove_file(&wdata->hdev->dev,

			   &dev_attr_bboard_calib);

err_free:

	input_free_device(wdata->extension.input);

	wdata->extension.input = NULL;
@@ -1462,6 +1526,8 @@ static void wiimod_bboard_remove(const struct wiimod_ops *ops, 


	input_unregister_device(wdata->extension.input);

	wdata->extension.input = NULL;

	device_remove_file(&wdata->hdev->dev,

			   &dev_attr_bboard_calib);

}



static const struct wiimod_ops wiimod_bboard = {